Tyndall National Institute is one of Europe's leading research centres, specialising in Information and Communications Technology (ICT) hardware. Tyndall has a critical mass of over 360 researchers, engineers, students and support staff placing a particular emphasis on quality, accomplishment and the delivery to Ireland of value from research. Tyndall’s areas of expertise range from micro-nanolectronics, microsystems, and photonics to theory modeling supported by a central fabrication facility.
Calculations show that electron states are not confined in the dashes in 1.55 mu m InAs/InP quantum dash-in-a-well laser structures. The combination of strain and three-dimensional confinement reduces the calculated density of states (DOS) near the valence band maximum, with the conduction and valence DOS then almost equal close to the band edges. Calculations and photoabsorption measurements show strongly polarized spontaneous emission and gain spectra. Experimental analysis shows the room temperature threshold current is dominated by nonradiative current paths. (C) 2008 American Institute of Physics. (DOI: 10.1063/1.2952194)